JP2013057872A - Electromagnetic driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic driving device capable of oscillating a movable member stably and effectively even at a high temperature without using a permanent magnet.SOLUTION: The electromagnetic driving device comprises: a lens holder 12 that is a movable member; and a case 11 that functions as a fixing member supporting the lens holder 12 in such a manner to allow the lens holder 12 to be oscillated. A driving plate-shaped repulsive member 15 made of a nonmagnetic conductive material is mounted to the case 11 and a driving coil 14 is attached to the lens holder 12 in such a way that the axial direction of the coil is in the thickness direction of the driving repulsive member 15, or the driving coil 14 is attached to the case 11 and the driving repulsive member 15 is mounted to the lens holder 12. An AC current is applied to the driving coil 14 to generate an eddy current in the driving repulsive member 15, thereby generating a repulsive force caused by the eddy current between the driving coil 14 and the driving repulsive member 15. The repulsive force moves the lens holder 12 in the axial direction of the lens holder 12.

Description

  The present invention relates to an electromagnetic drive device capable of performing automatic focus drive and suppression of camera shake, for example, for a photographing optical apparatus.

In recent years, a camera mounted on a mobile phone or the like has increased in the number of pixels of an image sensor, and the quality of captured images has been improved. Along with this, the lens system to be mounted is also shifting from the conventional fixed focus lens driving device to the movable focus lens driving device. This is because a fixed-focus lens driving device is out of focus and cannot cope with the resolution of a high pixel count image sensor.
The lens system in the movable focus lens driving device is driven by energizing a driving coil arranged in a magnetic field created by a permanent magnet and driving the driving coil by Lorentz force to move the lens holder in the direction of the optical axis of the lens. In many cases, a voice coil motor type lens driving device is used that is moved to (see, for example, Patent Document 1).
Cameras mounted on mobile phones and the like are prone to camera shake during shooting, and therefore have a function for suppressing camera shake by swinging the lens holder using a permanent magnet and a coil for suppressing camera shake. Optical devices have been proposed. Accordingly, in addition to the function of driving the lens holder in the optical axis direction of the lens, camera shake can be suppressed, so that a clear image can be formed on the image sensor (see, for example, Patent Document 2).
In addition, in recent years, the voice coil motor type lens driving device and electromagnetic driving device use a rare earth magnet having a high saturation magnetic flux density containing a large amount of rare earth elements such as a neodymium magnet as a permanent magnet in order to exert a large driving force. (For example, see Patent Document 3).

JP 2004-280031 A JP 2009-294393 A JP 2010-14920 A

However, the rare earth magnet has a low heat-resistant temperature, and is not only easily deteriorated during storage even at a temperature around 100 ° C., but also has a large temperature dependence of magnetic properties, so that the driving force changes during high-temperature operation. There was a problem.
The voice coil motor type lens driving device or electromagnetic driving device has a configuration in which a movable member such as a lens holder is swung by a Lorentz force generated at a part of a side of the driving coil, and thus driving efficiency is poor. There was a problem.

  The present invention has been made in view of conventional problems, and an object of the present invention is to provide an electromagnetic drive device that can stably swing a movable member even at a high temperature without using a permanent magnet. To do.

As a result of intensive studies, the inventor has used a pair of a coil and a nonmagnetic conductive member arranged so as to face the coil as electromagnetic drive means, and an eddy current is generated in the nonmagnetic conductive member by supplying an alternating current to the coil. If the repulsive force generated between the coil and the nonmagnetic conductive member by the demagnetizing field due to the eddy current is used as the driving force, a small and stable electromagnetic driving device that does not use a permanent magnet can be obtained. The present invention has been reached.
That is, the present invention provides an electromagnetic drive comprising a columnar or cylindrical movable member, a fixed member that supports the movable member in a swingable manner, and a drive unit that swings the movable member relative to the fixed member. The driving means includes a plate-like or annular driving repulsion member made of a nonmagnetic conductive material, and one or both of one side and the other side in the thickness direction of the driving repulsion member. And a driving coil arranged so that the axial direction of the winding faces the thickness direction of the driving repulsion member, and either one of the driving repulsion member or the driving coil acts as the movable member. It is mounted, and the other is mounted on the fixing member.

In this way, the plate-like drive repulsion member made of a nonmagnetic conductive material and the drive coil are arranged to face each other, and an alternating current is passed through the drive coil to generate an eddy current in the drive repulsion member. With this simple configuration, it is possible to obtain an electromagnetic drive device capable of giving the movable member swinging including a linear reciprocating motion and a pendulum motion involving rotation around an axis.

Further, the present invention is characterized in that the movable member is supported by a spring member so as to be swingable with respect to the fixed member.
As a result, the movable member can be swingably attached to the fixed member with a simple configuration.
In the present invention, the thickness direction of the drive repulsion member is the axial direction of the movable member, and the drive coil is disposed on one side and the other side of the drive repulsion member, A guide hole provided in the movable member and extending in the axial direction of the movable member, and a guide pin having both ends fixed to the fixed member and penetrating the guide hole are further provided.
As a result, the movable member moves between the repulsive force acting between the driving coil on one side and the driving repulsion member and the driving coil on the other side and the driving repulsion member in the axial direction of the movable member. Therefore, the movable member can be stably reciprocated in the axial direction of the movable member without attaching the movable member to the fixed member.

In the present invention, the thickness direction of the drive repulsion member is the axial direction of the movable member, and a plurality of sets of the drive repulsion member and the drive coil are arranged along the axial direction of the movable member In addition, a plate-like or annular support repulsion member made of a nonmagnetic conductive material and disposed so that the thickness direction is perpendicular to the axial direction of the movable member, and the thickness of the support repulsion member And at least three sets of supporting coils arranged so that the axial direction of the winding faces the thickness direction of the supporting repelling member, and any one of the supporting repelling member and the supporting coil One is attached to the movable member, and the other is attached to the fixed member.
As a result, the movable member floats so as to be movable in the axial direction of the movable member by a repulsive force acting between the three sets of the supporting repulsive member and the supporting coil, and a plurality of the driving repulsive members and the driving coils Therefore, the movable member can be stably reciprocated in the axial direction of the movable member without attaching the movable member to the fixed member.

In the present invention, the thickness direction of the drive repulsion member is the axial direction of the movable member, and the drive coil is disposed on one side and the other side of the drive repulsion member, Further provided on the inner peripheral side of the drive coil is a plate-like or annular support repulsion member made of a non-magnetic conductive material arranged so that the thickness direction is perpendicular to the axial direction of the movable member, One of the two types of repulsion members (drive repulsion part and support repulsion member) and the drive coil is mounted on the movable member, and the other is mounted on the fixed member.
Thus, the movable member floats movably in the axial direction of the movable member by a repulsive force acting between the driving coil and the supporting repulsive member, while the driving coil and the driving repelling member on one side are The reciprocating force acting between the driving coil on the other side and the repulsive force acting between the driving repulsion member move along a balanced position, so that the movable member can be moved without attaching the movable member to the fixed member. The movable member can be stably reciprocated in the axial direction.

Further, in the present invention, the driving repulsion member is an annular member having a truncated cone side surface and disposed coaxially with the movable member, and the driving coil is arranged in the thickness direction of the annular driving repulsion member. It arrange | positions at one side and the other side, respectively, and it arrange | positions so that the annular part of the said drive repulsion member may each oppose the winding part of the said two drive coils.
As a result, a repulsive force that intersects the axial direction of the movable member and is symmetric with respect to the axial direction acts on the movable member, so that the movable member floats so as to be movable in the axial direction. At a position where the axial component of the repulsive force acting between the driving coil and the driving repulsive member balances with the axial component of the repulsive force acting between the driving coil on the other side and the driving repulsive member Can be moved along. Therefore, the movable member can be stably reciprocated in the axial direction of the movable member without attaching the movable member to the fixed member.

In the present invention, the movable member is supported by the spring member so as to be swingable with respect to the fixed member, and the thickness direction of the driving repulsion member is set to a direction orthogonal to the axial direction of the movable member, The drive coil is arranged in the thickness direction of the drive repulsion member so that the axial direction of the winding faces the thickness direction of the drive repulsion member.
As a result, the movable member can be swung around an axis orthogonal to the axial direction of the movable member, so that the swing acting on the movable member can be effectively suppressed with a simple configuration.
Further, the present invention is made of a soft magnetic material on any one or a plurality or all of the inner peripheral side, the outer peripheral side, and the back side which is the surface opposite to the driving repulsion member. A core member is arranged.
Thereby, the AC magnetic field from the drive coil can be effectively guided to the drive repulsion member and the support repulsion member, so that the movable member can be efficiently swung. Further, since the magnetic field from the driving coil mainly passes through the core member, it has a so-called shielding effect that weakens the magnetic field outside the core member, so that leakage of the magnetic field from the driving coil can be reduced.
Further, the present invention provides a protruding portion that protrudes from the outer edge of the driving repulsion member to the outer peripheral side of the driving coil, or protrudes from the inner peripheral portion of the driving repulsive member to the inner peripheral side of the driving coil. Any one or both of the projecting portions are provided on the drive repulsion member.
Since the drive repulsion member also has a shielding effect, the leakage of the magnetic field from the drive coil can be reduced, and accordingly, the magnetic field applied to the drive repulsion member itself is strengthened, so that the movable member can be swung efficiently. be able to.

  The summary of the invention does not list all necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

It is a figure which shows the structure of the lens drive device which concerns on Embodiment 1 of this invention. FIG. 3 is an exploded perspective view of the lens driving device according to the first embodiment. It is a figure which shows the other shape of the repulsion member for a drive. It is a figure which shows an example of magnetic field distribution when alternating current is supplied to the coil for a drive. It is a figure which shows the relationship between the distance between a drive coil and a drive repulsion member, and thrust. It is a figure which shows the relationship between a drive current and the displacement amount of a lens holder. It is a figure which shows the relationship between the cross-sectional shape of a coil | winding part, and thrust. It is a figure which shows the structure of the lens drive device which concerns on Embodiment 2 of this invention. It is a figure which shows the other shape of a core member. It is a figure which shows an example of magnetic field distribution in case the soft-magnetic member is arrange | positioned only at the back side of the drive coil. 6 is a diagram illustrating an example of a magnetic field distribution when an alternating current is supplied to a driving coil according to Embodiment 2. FIG. It is a figure which shows an example of magnetic field distribution at the time of using the drive repulsion member which has a protrusion part in the inner edge part and outer edge part of a ring part. It is a figure which shows the relationship between the distance between the drive coil and drive repulsion member in Embodiment 2, and thrust. FIG. 10 is a diagram illustrating a relationship between a driving current and a lens holder displacement amount in the second embodiment. It is a figure which shows an example of the magnetic field distribution at the time of making the inner wall part and outer wall part of a core member oppose a drive repulsion member. It is a figure which shows the relationship between the distance between the drive coil and drive repulsion member in the structure of FIG. 15, and thrust. It is a figure which shows the structure of the lens drive device which concerns on Embodiment 3 of this invention. It is a figure which shows the other structure of the lens drive device by this invention. It is a figure which shows the structure of the electromagnetic drive device which concerns on Embodiment 4 of this invention. It is a figure which shows the structure of the electromagnetic drive device of the simple structure by this invention. It is a figure which shows the structure of the electromagnetic drive device which concerns on this Embodiment 5. FIG. It is a figure which shows the structure of the camera-shake suppression apparatus which concerns on this Embodiment 6. FIG. It is a figure which shows the structure of the electromagnetic drive device which concerns on this Embodiment 7. FIG.

  Hereinafter, the present invention will be described in detail through embodiments, but the following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

Embodiment 1 FIG.
FIG. 1 is a longitudinal sectional view showing a configuration of a lens driving device 10 as an electromagnetic driving device according to Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view.
The lens drive device 10 includes a case 11 as a fixed member, a lens holder 12 as a movable member, spring members 13A and 13B as support means for suspending the lens holder 12 on the case 11, a drive coil 14, and a drive. A repulsion member 15.
Hereinafter, the axial direction of the lens holder 12, that is, the subject side when the lens 16 is mounted on the lens holder 12, is defined as the front in the Z-axis direction (+ Z side), and the two directions orthogonal to the Z-axis are the X-axis and Y-axis, respectively. To do. In FIG. 1, the lens 16 is omitted.

The case 11 includes a cylindrical frame 11a, a cylindrical cover 11b that is disposed on the subject side (+ Z side) of the frame 11a, an opening is formed on the + Z side, and the lens holder 12 side is open. A base portion 11c having an opening formed on the rear side (-Z side) disposed on the -Z side of 11a and the lens holder 12 side being opened. A step portion 11k for attaching the drive coil 14 is provided at the peripheral edge of the opening of the base portion 11c.
The lens holder 12 includes, for example, a cylindrical main body 12a, and holds a lens formed of a combination of an objective lens and an eyepiece lens inside the main body 12a. In this example, a step portion 12b having a diameter smaller than the diameter of the main body 12a is provided on the rear side (−Z side) of the main body 12a, and the driving repulsion member 15 is attached to the step portion 12b.
The spring members 13A and 13B have four substantially arc-shaped arm portions that connect the annular outer peripheral portion 13a and the inner peripheral portion 13b, and the outer peripheral portion 13a and the inner peripheral portion 13b, which are arranged on the inner side and the outer side, respectively. 13c. The outer peripheral portion 13 a is fixed to the case 11, and the inner peripheral portion 13 b is fixed to the lens holder 12. The four arm portions 13 c function as springs that suspend the lens holder 12 from the case 11.

The driving coil 14 is wound around the Z axis and attached to a step portion 11k provided on the base portion 11c of the case 11. An alternating current having a frequency determined by the material and thickness of the driving repulsion member 15 is supplied to the driving coil 14.
The drive repulsion member 15 is an annular member made of a non-magnetic conductive material provided on the step portion 12b of the lens holder 12 and attached so that the thickness direction is the Z-axis direction. It arrange | positions so that it may oppose in a Z-axis direction in a line end surface. As the nonmagnetic conductive material suitably used for the driving repulsion member 15, for example, a nonmagnetic material having a small specific resistance, such as copper or aluminum, is used.
Since the skin depth to which the eddy current reaches is determined by the frequency and the specific resistance of the nonmagnetic conductive material, the eddy current can be effectively generated by making the thickness of the driving repulsion member 15 equal to or greater than the skin depth. When the drive repulsion member 15 is made of, for example, copper, the relationship between the frequency of the alternating current supplied to the drive coil 14 and the thickness of the drive repulsion member 15 is, for example, 2 mm or more at 1 kHz and 0. If it is 2 mm or more and 10 MHz, it may be 20 μm or more.
In the case of aluminum, the specific resistance is about 1.7 times that of copper, so the thickness may be 1.3 times that of copper.

When an alternating current is supplied to the driving coil 14, an eddy current is generated in the driving repulsion member 15. This eddy current generates a magnetic field (demagnetizing field) that tends to weaken the magnetic field generated by the driving coil 14, and as a result, repulsive force is generated between the driving coil 14 and the driving repulsion member 15.
In this example, the driving coil 14 is attached to the case 11 that is a fixed member, and the driving repulsion member 15 is attached to the lens holder 12 that is a movable member. Therefore, when an alternating current is supplied to the driving coil 14, The repulsive force is a thrust that pushes the lens holder 12 forward in the Z-axis direction (+ Z side), and the lens holder 12 can be moved to a position that balances with the restoring force of the front and rear spring members 13A and 13B. Since the restoring force of the spring members 13A and 13B always acts on the lens holder 12 in the -Z direction, the lens holder 12 can be moved in the -Z direction if the current value supplied to the driving coil 14 is reduced. Can be made.
Therefore, it is possible to obtain the lens driving device 10 that can automatically focus drive the lens holder 12 in the subject direction with a simple configuration and without using a permanent magnet.

In the first embodiment, the driving coil 14 is attached to the case 11 and the driving repulsion member 15 is attached to the lens holder 12. However, the driving coil 14 is attached to the lens holder 12 and the driving repulsion member 15 is attached to the case. The same effect can be obtained even if it is attached to 11. Also in this case, it is important to arrange the annular portion of the drive repulsion member 15 so as to face the Z-axis direction on the winding end face of the drive coil 14. An eddy current can be generated to move the lens holder 12 toward the subject.
In the above example, the inner and outer diameters of the winding portion of the driving coil 14 as viewed from the Z-axis direction and the inner and outer diameters of the driving repulsion member 15 as viewed from the Z-axis direction. However, if the annular portion of the drive repulsion member 15 is arranged to face the winding portion of the drive coil 14, the size of the drive coil 14 and the size of the drive repulsion member 15 are the same. May be different.
Further, in the above example, the driving repulsion member 15 is an annular member as shown in FIG. 3A. However, as shown in FIG. As shown, a plurality of arc-shaped members may be annularly arranged. Further, when the shape of the drive coil 14 is a square shape, the drive repulsion member 15 may be a square annular member as shown in FIG. 3D or a rectangular shape as shown in FIG. What is necessary is just to select suitably according to the shape of the coil 14 for a drive, such as using the plate shape and what used several rod-shaped members arranged in a rectangular shape as shown in FIG.3 (f).
Alternatively, as shown in FIG. 3G, the drive repulsion member 15 is formed as an annular member having a recess 15s so as to surround the winding portion of the drive coil 14 disposed in the recess 15s. Also good. Further, the drive repulsion member 15 may have a configuration in which a plurality of arc-shaped members formed with recesses 15s similar to those in FIG.

[Experimental Example 1]
FIG. 4 is a diagram showing an example of a magnetic field distribution when an alternating current is supplied to the driving coil 14. The driving coil 14 has an inner diameter of 6 mm, an outer diameter of 14 mm, and a thickness of 0.6 mm. The one in which a coated conductor was wound was used. The frequency of the alternating current is 100 kHz. Further, as the driving repelling member 15, an annular member made of copper and having an inner diameter of 6 mm, an outer diameter of 14 mm, and a thickness of 0.3 mm was used.
In the lens driving device 10 of the present invention, the driving repulsion member 15 is disposed so that the annular portion thereof faces the winding end surface of the driving coil 14, and an alternating current is supplied to the driving coil 14, thereby An eddy current is generated in the drive repulsion member 15 by changing the magnetic field passing through the drive repulsion member 15 which is a magnetic conductive member. As a result, a repulsive force due to an eddy current is generated between the driving repulsion member 15 attached to the lens holder 12 as a movable member and the driving coil 14 attached to the case 11 as a fixed member. This is a thrust for moving the lens holder 12 as a movable member in the Z-axis direction.
FIG. 5 shows the size of the gap between the driving coil 14 and the driving repulsion member 15 by supplying an alternating current of 100 kHz and about 720 AT (ampere turn) to the driving coil 14 (gap length g shown in FIG. 4). FIG. 6 is a diagram showing a change in the magnitude of thrust (mN) per AT acting on the lens holder 12 when the angle is changed. FIG. 6 shows the magnitude of the drive current (AT) and the displacement amount (mm) of the lens holder 12. FIG. Note that the spring coefficient of the spring members 13A and 13B at this time is 0.04 N / mm.
As shown in FIGS. 5 and 6, since the eddy current generated in the driving repulsion member 15 can give a sufficient thrust to the lens holder 12, the lens holder can be electromagnetically driven without using a permanent magnet. It was confirmed that a practical lens driving device can be obtained.

The ratio of the width X _w and thickness Y _w of the winding portion of the driving coil 14 shown in FIG. 5, it may be determined flattened or elongated, or the like as appropriate in consideration of the relationship with the surrounding member, the current it is preferred that emphasizes efficiency determines the width X _w and thickness Y _w.
FIG. 7 shows an example of changes in thrust when the cross-sectional area (X _w · Y _w ) of the winding portion is maintained at 2.4 mm ² and the width X _w and the thickness Y _w are changed. Is the coil width X _w (mm), and the vertical axis is the thrust (mN / AT). In FIG. 7, the dimensions of the drive repulsion member 15 are the same as those in FIGS. As shown in FIG. 7, as the shape of the driving coil 14, it can be seen that a larger thrust can be obtained when the driving coil 14 is flat than when it is vertically long. It can also be seen that when the coil is flat and the coil width _Xw is 2 mm or more, the thrust has a small change in the thrust with respect to the change in the coil width.
Also, as shown in the magnetic field distribution diagram of FIG. 4, the magnetic field outside the drive repulsion member 15 is weaker than the magnetic field on the opposite side of the drive coil 14 from the drive repulsion member 15, so It can be seen that the drive repulsion member 15, which is a member, has a magnetic shield effect that blocks the magnetic field generated by the drive coil 14.

Embodiment 2. FIG.
In the first embodiment, the driving coil 14 is an air-core coil. However, as shown in FIG. 8, the inner and outer peripheral sides of the driving coil 14 are opposite to the driving repulsion member (hereinafter referred to as the rear surface). If the core member 17 made of a soft magnetic material is disposed on the side, the AC magnetic field from the drive coil 14 can be effectively guided to the drive repulsion member 15.
In the lens driving device 10Y of this example, a flange portion 12c that protrudes radially outward is provided in the approximate center of the main body 12a of the lens holder 12, and a driving repulsion member 15 is attached to the opposite side of the flange portion 12c from the subject side. In addition, a recess 11j is provided instead of the stepped portion 11k, and the driving coil 14 and the core member 17 are attached to the recess 11j. In the case 11 of this example, the length of the side surface of the base portion 11c in the Z-axis direction is increased, and the frame body 11a is omitted.
The core member 17 includes an annular base portion 17a, and an inner wall portion 17b and an outer wall portion 17c that protrude forward from the inner edge portion and the outer edge portion of the base portion 17a. The base portion 17a, the inner wall portion 17b, A housing recess 17k for housing the winding portion of the driving coil 14 is formed by the outer wall portion 17c. In this example, the depth of the concave portion 17k of the core member 17 is increased so that the annular portion of the driving repulsion member 15 is also accommodated in the concave portion 17k.
Thereby, the winding end face of the driving coil 14 is disposed so as to face the annular portion of the driving repulsion member 15, and the inner and outer peripheral sides of the driving driving coil 14, the rear side in the Z-axis direction, and The soft magnetic material is disposed on the inner peripheral side and the outer peripheral side of the annular portion of the drive repulsion member 15. As a result, since the magnetic field from the driving coil 14 is guided to the core member 17 made of a soft magnetic material and guided to the driving repulsion member 15, the magnetic flux density of the magnetic field applied to the driving repulsion member 15 can be increased. it can. Therefore, even if an AC current having the same magnitude as that without the core member 17 is applied to the driving coil 14, the repulsive force acting between the driving coil 14 and the driving repulsion member 15, that is, the lens holder 12 is applied. Since the acting thrust can be increased, the driving efficiency can be greatly increased.
In addition, as a material which comprises the core member 17, it is preferable to use a material with comparatively large specific resistance, such as a ferrite and silicon steel.

In the second embodiment, the driving coil 14 and the core member 17 are attached to the case 11 and the driving repulsion member 15 is attached to the lens holder 12. However, the driving repulsion member 15 is attached to the case 11, The driving coil 14 and the core member 17 may be attached to the lens holder 12.
Further, the shape of the core member 17 is not limited to the above example. For example, as shown in FIG. 9A, the core member 17 is an annular member having a diameter smaller than the inner diameter of the driving coil 14. Even if the core member 17 is disposed only on the inner peripheral side of the driving coil 14, the magnetic flux density of the magnetic field applied to the driving repulsion member 15 can be increased. Conversely, as shown in FIG. 9B, the core member 17 is an annular member having a diameter larger than the outer diameter of the driving coil 14, and the core member 17 is disposed only on the outer peripheral side of the driving coil 14. May be. 9A and 9B, the length of the core member 17 in the Z-axis direction may be a length that extends from the inner peripheral side of the driving coil 14 and reaches the driving repulsion member 15. .
Moreover, you may use the core member 17 with a shallow depth of the recessed part 17k as shown in FIG.9 (c).
Alternatively, a core member 17 having a hollow portion 17s including the winding portion of the drive coil 14 and the drive repulsion member 15 as shown in FIG. 9D may be used.
Moreover, it is good also as a structure which arrange | positions the annular | circular shaped core member 17 only to the back side of the drive coil 14 as shown in FIG.9 (e).
Furthermore, a core member 17 having a configuration in which the inner wall portion 17b and the outer wall portion 17c face the driving repulsion member 15 as shown in FIG. 9 (f) may be used.

[Experiment 2]
FIG. 10 is a diagram illustrating an example of a magnetic field distribution when a soft magnetic member is disposed only on the back side of the driving coil 14. The dimensions of the drive coil 14 and the dimensions and material of the drive repulsion member 15 are the same as in the first experimental example. In addition, the core member 17 has the same inner diameter of 6 mm and an outer diameter of 14 mm as that of the driving coil 14. As is clear from comparison between FIG. 10 and FIG. 4, the arrangement of the core member 17 increases the magnetic flux density of the magnetic field applied to the drive repulsion member 15 and uses the air-core coil of FIG. 4 for the thrust. It was confirmed that it was about 1.3 times that of
Further, by arranging the soft magnetic member on the back side, the AC magnetic field shielding effect becomes more effective, and the magnetic field on the back side of the core member 17 is greatly weakened.
FIG. 11 is a diagram illustrating an example of a magnetic field distribution when an alternating current is supplied to the driving coil 14 in which the soft magnetic material is disposed on the inner peripheral side, the outer peripheral side, and the back side, which is described in the lens driving device 10Y. is there. The dimensions of the drive coil 14 and the dimensions and material of the drive repulsion member 15 are the same as in the first experimental example. The core member 17 used had an outer diameter of 14.8 mm, an inner diameter of 5.2 mm, a recess depth of 1.35 mm, and a wall thickness of 0.3 mm. As is clear from comparison between FIG. 11 and FIG. 10, the magnetic flux density of the magnetic field applied to the drive repulsion member 15 is increased by arranging soft magnetic materials on the inner and outer peripheral sides in addition to the back side. It was confirmed that it was even higher. In addition, it was confirmed that the thrust is further larger than that in the case where the soft magnetic member is arranged on the back side in FIG. 10 and is about 1.5 times that in the case where the air-core coil in FIG. 4 is used.
In addition, as shown in FIG. 12, an annular core member 17 is disposed on the back side of the driving coil 14, and the driving coil 14 and the core are formed from the inner edge and the outer edge of the annular portion of the driving repulsion member 15. Even if the projecting portions 15m and 15n projecting on the inner peripheral side and the outer peripheral side of the member 17 are provided, the magnetic flux density of the magnetic field applied to the driving repulsion member 15 can be increased and the driving coil 14 can be increased. The alternating magnetic field around can be reduced.
In this case, the shielding effect is larger than when the annular core member 17 is arranged on the back side of the driving coil 14 in FIG. 10, but the thrust is smaller than in the case of FIG.

Further, FIG. 13 shows the drive coil 14 and the drive in the configuration (configuration of the second embodiment) in which soft magnetic materials are arranged on the inner peripheral side, the outer peripheral side, and the rear side of the drive coil 14 shown in FIG. FIG. 14 is a diagram showing a change in the magnitude of the thrust acting on the drive repulsion member 15 when the gap length g with the repulsion member 15 is changed. FIG. It is a figure which shows the relationship with a displacement amount. The spring coefficients of the spring members 13A and 13B are the same as those in Experimental Example 1 and are 0.04 N / mm.
As shown in FIG. 13, it was confirmed that the thrust applied to the lens holder 12 can be increased by arranging soft magnetic materials on the inner circumferential side, outer circumferential side, and rear side of the driving coil 14. Further, since the change in thrust is small even when the cap length g is increased, a stable thrust can be obtained as compared with the case where the core member 17 is not provided. Further, as shown in FIG. 14, since the displacement sensitivity is also improved, the apparatus can be downsized as compared with the case where an air-core coil is used.
As shown in FIG. 15, if the inner wall 17b and the outer wall 17c of the core member 17 are opposed to the driving repulsion member 15, the inner wall 17b and the outer wall 17c are for driving. The thrust applied to the lens holder 12 can be further increased as compared with the case where the repulsion member 15 is positioned at the inner edge and the outer edge of the annular portion (FIG. 11; configuration of the second embodiment).
FIG. 16 is a diagram illustrating the relationship between the distance between the driving coil and the driving repulsion member and the thrust when the inner wall portion 17b and the outer wall portion 17c of the core member 17 are opposed to the driving repulsion member 15. 15 and 16, the drive repulsion member 15 has an outer diameter of 14 mm, an inner diameter of 6 mm, and a thickness of 0.3 mm. The drive coil 14 has an outer diameter of 12.4 mm and an inner diameter of 15 mm. A 7.6 mm, 1 mm thick, and 2.4 mm ² cross-sectional area winding portion was used. The core member 17 used had an outer diameter of 14 mm, an inner diameter of 6 mm, a recess depth of 1.1 mm, and a wall thickness of 0.7 mm.
As can be seen from FIG. 16, the thrust applied to the lens holder 12 is further increased as compared with the configuration of the second embodiment shown in FIG.

Embodiment 3 FIG.
FIG. 17 is a longitudinal sectional view showing the configuration of the lens driving device 20 according to Embodiment 3 of the present invention. In FIG. 17, 21 is a case as a fixed member, 22 is a lens holder as a movable member, and 24A is the front. A driving coil, 24B is a rear driving coil, 25 is a driving repulsion member, 26 is a guide hole, and 27 is a guide pin.
The case 21 is disposed on the subject side (+ Z side), a cylindrical cover portion 21b having an opening formed on the + Z side and the lens holder 22 side being opened, and a rear side disposed on the −Z side of the cover portion 21b. A base portion 21c having an opening formed on the side (−Z side) and an open side on the lens holder 22 side.
The lens holder 22 includes a main body 22a, an attachment portion 22b, an attachment recess 22c, and a guide hole 26. The main body 22a is a cylindrical member that holds a lens composed of a combination of an objective lens and an eyepiece lens on the inner side, and the attachment portion 22b is provided so as to protrude radially outward from the outer periphery on the + Z side of the main body 22a. The attachment recess 22c is a recess formed substantially at the center of the outer periphery of the attachment portion 22b, and the drive repulsion member 25 is attached to the attachment recess 22c.
The guide hole 26 is a hole that penetrates the lens holder 22 so as to extend in the axial direction of the lens holder 22, and is formed between the mounting recess 22c and the main body 22a.
On the other hand, the guide pin 27 is a rod-shaped member that penetrates the guide hole 26, and both ends thereof are fixed to the cover portion 21b and the base portion 21c of the case 21, respectively.

The front and rear drive coils 24A and 24B have the same configuration as that of the drive coil 14 of the first and second embodiments, and are wound around the Z axis so that the −Z side of the cover portion 21b and the + Z side of the base portion 21c. And are arranged respectively.
The drive repulsion member 25 is an annular member made of a nonmagnetic conductive material, like the drive repulsion member 15 of the first and second embodiments, and the thickness direction of the mounting recess 22c of the lens holder 22 is the Z-axis direction. Mounted to become.
That is, in this example, the drive repulsion member 25 is attached to the outer peripheral side of the lens holder 22 so that the thickness direction thereof is directed to the axial direction of the lens holder 22 which is a movable member, and the front drive coil 24A is attached to the drive repulsion member. 25 is arranged on the + Z side, and the rear drive coil 24B is arranged on the −Z side. The drive repulsion member 25 and the front and rear drive coils 24A and 24B are arranged such that the annular portion of the drive repulsion member 25 and the winding end faces of the front and rear drive coils 24A and 24B face each other. The lens holder 22 and the case 21 are respectively attached.

By adopting such a configuration, a repulsive force in the −Z direction acts on the driving repulsion member 25 from the front drive coil 24A, and a repulsive force in the + Z direction acts on the rear drive coil 24B. When the drive coils 24A and 24B are energized and one current value is made larger than the other current value, the drive repulsion member 25 is subjected to a thrust toward the drive coil having the smaller current value. . Accordingly, the lens holder 22 moves along the guide pin 27 toward the driving coil having the smaller current value.
By the way, the repulsive force acting between the front and rear drive coils 24A and 24B and the drive repulsion member 25 increases as the distance between the front and rear drive coils 24A and 24B and the drive repulsion member 25 decreases. Therefore, when the lens holder 22 moves toward the driving coil having the smaller current value, the repulsive force from the driving coil having the smaller current value increases. As a result, the lens holder 22 moves to a position where the repulsive force from the driving coil having the larger current value and the repulsive force from the driving coil having the smaller current value balance, and stops. Therefore, the lens holder 22 can be moved to a desired position without using a spring member.
The lens holder 22 normally has only a repulsive force in the −Z direction and the + Z direction. However, depending on the direction of the lens driving device 20, the guide pin 27 may move while contacting the inside of the guide hole 26. Therefore, it is preferable to reduce a loss due to contact friction by applying a lubricant inside the guide hole 26 or using a resin having lubricity as the guide pin 27.

  In the third embodiment, the drive repulsion member 25 is attached to the lens holder 22 and the front and rear drive coils 24A and 24B are attached to the case 21. However, the drive coil is the outer periphery of the lens holder 22. It is good also as a structure attached to the side and attaching the repulsion member for a drive to the case 21. FIG. In this case, the front and rear driving coils 24A and 24B are arranged on the + Z side and the −Z side of the lens holder 22, respectively, and the driving repulsion member 25 is arranged at the center of the case 21 at the front and rear driving coils 24A. , 24B and the drive repulsion member 25. As a result, a thrust in the + Z direction acts on the front drive coil 24A, and a thrust in the −Z direction acts on the rear drive coil 24B. Therefore, as in the third embodiment, the lens holder 22 is connected to the current The repulsive force from the driving coil having the larger value can be moved to a position where the repulsive force from the driving coil having the smaller current value is balanced.

In the above example, the lens holder 22 is configured to move while sliding along the guide pin 27. However, as shown in FIG. 18, the guide pin 27 is made of a nonmagnetic conductive material, and the guide hole 26 is formed. If the pin coil 28 wound around the Z-axis is provided and an alternating current is supplied to the pin coil 28 when the lens holder 22 is driven, the lens holder 22 can be smoothly moved along the guide pin 27. Can be moved to.
That is, the pin coil 28 is disposed so that the winding surrounds the guide pin 27, and an alternating current is supplied to the pin coil 28. A repulsive force toward the center acts. Since the guide pin 27 is fixed to the case 21 that is a fixed member and the pin coil 28 is attached to the lens holder 22 that is a movable member, the lens holder 22 moves while receiving a repulsive force from the guide pin 27. Accordingly, there is no contact friction between the guide hole 26 and the guide pin 27, so that the lens holder 22 can be smoothly moved along the guide pin 27.

Embodiment 4 FIG.
19 (a) and 19 (b) are diagrams showing the configuration of the electromagnetic drive device 30 according to Embodiment 4 of the present invention. FIG. 19 (a) is a longitudinal sectional view, and FIG. 19 (b) is an exploded perspective view. .
The electromagnetic drive device 30 includes a fixed member 31, a movable member 32, front and rear drive coils 33A and 33B, front and rear support coils 34A and 34B, front and rear drive repulsion members 35A and 35B, A drive core member 36 and front and rear support core members 37A and 37B are provided.
The fixed member 31 is a cylindrical member, and the movable member 32 is a cylindrical or columnar member disposed coaxially with the fixed member 31 inside the fixed member 31. Hereinafter, the axial direction of the fixed member 31 and the movable member 32 is the Z-axis direction, and the upward direction in FIG. 19 is the Z-axis front (+ Z side).
The fixing member 31 includes a cylindrical upper fixing member 31a in which a step portion 31p having a larger inner diameter than the inner diameter on the + Z side is formed on the −Z side, and a step portion 31q having a larger inner diameter on the + Z side than the inner diameter on the −Z side. And a cylindrical lower fixing member 31b.
The movable member 32 is a cylindrical member made of a non-magnetic conductive material. In this example, as shown in FIG. 19, the movable member 32 is composed of three cylindrical portions, that is, an upper portion 32a, an intermediate portion 32b, and a lower portion 32c. Divided between the end portion on the −Z side of the upper side portion 32a and the annular front drive repulsion member 35A and the end portion on the + Z side of the lower side portion 32c and the intermediate portion 32b. The parts to which the rear drive repulsion member 35B is attached are fabricated and assembled.

The front and rear drive coils 33A and 33B are both wound around the + Z-axis direction and attached to the drive core member 36 at a predetermined distance, and are formed on the fixed member 31 together with the drive core member 36. It is attached to the step portions 31p and 31q. The driving core member 36 is disposed between the inside and outside of the front and rear driving coils 33A and 33B and between the front and rear driving coils 33A and 33B, and generates a magnetic field generated by the front and rear driving coils 33A and 33B. By effectively leading to the above, the magnetic flux density of the magnetic field applied to the front and rear driving repulsion members 35A and 35B is increased.
On the other hand, the front support coil 34A is attached to the inner peripheral side of the front support core member 37A that is wound in the + Z-axis direction and attached to the inner side of the upper portion of the upper fixing member 31a. It is attached to the inner peripheral side of the rear support core member 37B that is wound in the + Z-axis direction and attached to the inside of the lower portion of the lower fixing member 31b. The front and rear support core members 37A and 37B are arranged on the + Z side, the -Z side, and the outer peripheral side of the front and rear support coils 34A and 34B, and are generated by the front and rear support coils 34A and 34B. Is effectively guided to the upper part 32 a and the lower part 32 c of the movable member 32, respectively, so that the magnetic flux density of the magnetic field applied to the movable member 32 is increased.
Clearances are provided between the movable member 32 and the driving core member 36, and between the movable member 32 and the front and rear support coils 34A and 34B. Here, s is the size of the gap between the movable member 32 and the front and rear support coils 34A and 34B. The size of the gap between the movable member 32 and the driving core member 36 may be s or more.
Both the front and rear drive repulsion members 35A and 35B are made of a non-magnetic conductive material, and are annular members whose inner peripheral side is attached to the movable member 32 and protrudes to the inner peripheral side of the fixed member. Similar to the first to third embodiments, the annular portions are arranged so as to face the winding portions of the front and rear drive coils 33A and 33B, respectively. Specifically, the annular portion of the front drive repulsion member 35A is disposed on the + Z side of the front drive coil 33A so as to face the winding portion of the front drive coil 33A, and the rear drive repulsion member The annular portion of 35B is arranged on the −Z side of the rear drive coil 33B so as to face the winding portion of the rear drive coil 33B.

Next, the operation of the electromagnetic drive device 30 will be described.
First, by applying an alternating current to the front and rear support coils 34A and 34B, an eddy current is applied to the movable member 32 made of a nonmagnetic conductive material disposed to face the front and rear support coils 34A and 34B. generate. The magnetic fields from the front and rear support coils 34A and 34B are effectively guided to the upper part 32a and the lower part 32c of the movable member 32 by the front and rear support core members 37A and 37B, respectively. A repulsive force toward the center of the movable member 32 acts on the upper side portion 32 a and the lower side portion 32 c of the 32. The repulsive forces acting between the front and rear support coils 34A and 34B and the movable member 32 made of a nonmagnetic conductive material are balanced at the coaxial position, and between the front and rear support coils 34A and 34B and the movable member 32. The closer the distance, the larger. Therefore, when the movable member 32 is decentered from the central axis and approaches either one of the front support coil 34A or the rear support coil 34B, the repulsive force at that portion increases and the movable member 32 is pushed back to the center.
Thus, the repulsive force caused by the eddy current generated in the upper side portion 32a and the lower side portion 32c of the movable member 32 maintains the support posture of the movable member 32 like a spring and holds the movable member 32 on the central axis. Even without a member or guide pin, the movable member 32 can be held on the central axis. That is, the movable member 32 can be floated in the air while maintaining a predetermined gap s from the inner peripheral surfaces of the front and rear support coils 34A and 34B.

Next, when an alternating current is applied to each of the front and rear drive coils 33A and 33B, a repulsive force in the + Z direction acts on the front drive repulsion member 35A disposed on the + Z side of the front drive coil 33A. A repulsive force in the -Z direction acts on the rear drive repulsion member 35B disposed on the -Z side of the drive coil 33B. Therefore, if the current value applied to one of the front and rear drive coils 33A and 33B is made larger than the current value applied to the other, a thrust toward the drive coil with the smaller current value acts on the movable member 32. Therefore, after the movable member 32 moves to the driving coil having the smaller current value, the repulsive force from the driving coil having the larger current value is balanced with the repulsive force from the driving coil having the smaller current value. Still at position.
At this time, since the movable member 32 is held on the central axis by the repulsive force from the front and rear support coils 34A and 34B, the movable member 32 can be moved in the Z-axis direction without friction.
The drive core member 36 and the front and rear support core members 37A and 37B may be omitted, but as in this example, the drive core member 36 and the front and rear support core members If 37A and 37B are provided, driving efficiency can be improved.

By the way, when the total current value, which is the sum of the current value supplied to the front drive coil 33A and the current value supplied to the rear drive coil 33B, is small, the spring-like property is a weak spring. The time required for the vibrations of the time to settle and rest becomes longer. On the other hand, when the total current value is large, the spring-like property is a strong spring, so that the time required to stop is shortened.
That is, in the electromagnetic drive device 30 of the fourth embodiment, unlike the conventional spring-suspended electromagnetic drive device, the spring characteristics are changed by controlling the total current value of the front and rear drive coils 33A and 33B. be able to. Accordingly, the spring strength can be increased or decreased as necessary, so if the movable member 32 is moved while increasing / decreasing the total current value, the movable member 32 can be moved to a gentle state and then suddenly stopped. Various operations can be performed.

In Embodiment 4, the front and rear drive coils 33A and 33B and the front and rear support coils 34A and 34B are used to hold the movable member 32 on the central axis in the Z-axis direction. Although it was made to move, it is good also as a structure which shares a drive coil and a support coil.
FIG. 20A is a diagram showing the configuration of an electromagnetic drive device 30D having a simple structure as an example, in which 31 is a cylindrical fixed member, and 32 is a cylindrical movable member made of a nonmagnetic conductive material. 33U and 33D are front and rear coils wound around the Z axis, 35 is an annular repulsion member made of a nonmagnetic conductive material, and 36 is a core member made of a soft magnetic material.
In the electromagnetic drive device 30D having a simple structure, the repulsion member 35 is attached to the center of the outer peripheral portion of the movable member 32, the front coil 33U is disposed on the + Z side of the repulsion member 35, and the rear coil 33D is disposed on the −Z side. ing. The front coil 33U and the rear coil 33D are mounted in a recess of the core member 36 attached to the inner wall of the fixing member 31.
FIG. 20B is a diagram illustrating an example of a magnetic field distribution generated when an alternating current is applied to the front coil 33U and the rear coil 33D. From FIG. 20B, the center of the magnetic flux generated by the front coil 33U and the rear coil 33D is separated from the movable member 32 and the repulsion member 35 made of a nonmagnetic conductive material. And it can be understood that a repulsive force acts toward the central axis of the movable member.
As described above, also in the electromagnetic drive device 30D having a simple structure, by applying an alternating current to the front and rear coils 33D and 34U, a repulsive force directed to the central axis direction acts on the movable member 32 and the repulsive member 35 is also affected. Since a repulsive force in the −Z direction acts from the front coil 33U and a repulsive force in the + Z direction acts on the rear coil 33D, the movable member 32 is controlled by controlling the current value supplied to the front and rear coils 33U and 33D. It can be moved in the Z-axis direction while being held on the central axis.
The alternating current applied to each of the front and rear coils 33U and 33D may have any phase relationship, and may have different frequencies.

In the electromagnetic drive device 30 of the fourth embodiment and the electromagnetic drive device 30D having the simple structure, if the movable member 32 is a lens holder and the fixed member is a case, a spring member or a guide pin is not used, and the air floating A mold lens driving device can be configured.
Further, if the movable member 32 is extended to the front and rear of the fixed member 31, and this is used as a movable shaft, a linear actuator having a short stroke but no sliding resistance can be configured.
Further, the electromagnetic drive device 30 of the fourth embodiment and the electromagnetic drive device 30D having the simple structure may be manufactured by assembling individually manufactured parts, but as MEMS (Micro Electro Mechanical Systems), silicon or the like It may be manufactured as a wafer level electromagnetic driving device using a technique similar to that of the integrated circuit.

Embodiment 5 FIG.
In the electromagnetic drive device 30D having the simple structure, the movable member 32 is held on the central axis by the front and rear coils 33U and 33D and the movable member 32 made of a nonmagnetic conductive material, and the front and rear coils 33U and 33D and the repulsion member 35 are retained. The movable member 32 is moved in the Z-axis direction as shown in FIGS. 21 (a) and 21 (b). As shown in FIGS. 21 (a) and 21 (b), the front and rear coils 33P and 33Q having a truncated cone side shape (conical shape) and the truncated cone are used. If the side-shaped repulsive member 35R is used, an electromagnetic drive device 30C that can be driven in the Z-axis direction while holding the movable member 32 on the central axis without using a movable member made of a nonmagnetic conductive material is configured. can do.
At this time, it is important to dispose the annular portion of the repulsion member 35R so as to face the winding portion between the winding portion of the front coil 33P and the rear coil 33Q. Since the normal line of each side surface of the repulsion member 35R and the rear coil 33Q and the axis line of the movable member 32 intersect, when the front coil 33P and the rear coil 33Q are energized, the repulsion member 35R is shown in FIG. ), A repulsive force in a direction intersecting the axis of the movable member 32 acts. The Z-axis direction component of this repulsive force becomes a thrust force that moves the movable member 32 along the Z-axis direction, and a component in a direction perpendicular to the Z-axis becomes a holding force that holds the movable member 32 on the central axis of the movable member 32. Therefore, even if the movable member 32 is not a nonmagnetic conductive member, it can be driven in the Z-axis direction while holding the movable member 32 on the central axis.
The inner diameter and outer diameter of the front coil 33P, the repulsion member 35R, and the rear coil 33Q may be increased in the order of the front coil 33P, the repulsion member 35R, and the rear coil 33Q, as shown in FIG. However, they may be the same as shown in FIG.
Also in the electromagnetic drive device 30C of this example, if the movable member 32 is a lens holder and the fixed member 31 is a case, an airborne lens drive device that does not use a spring member or a guide pin can be configured. .

Embodiment 6 FIG.
22 (a) and 22 (b) are diagrams showing a configuration of a camera shake suppression device 40 as an electromagnetic drive device according to Embodiment 6 of the present invention. FIG. 22 (a) is a longitudinal sectional view, and FIG. It is a disassembled perspective view.
The camera shake suppression device 40 includes a fixed member 41, a lens driving device 42 as a movable member, a swinging spring member 43 that suspends the lens driving device on the fixed member 41, and first to fourth swinging coils 441 to 444. And first to fourth swinging repulsion members 451 to 454. For the sake of simplicity, only the case for supporting the lens holder is shown for the lens driving device 42.
Hereinafter, the axial direction of the lens driving device 42 is defined as the front (+ Z side) in the Z-axis direction, and the two directions orthogonal to the Z-axis are defined as the X-axis and the Y-axis, respectively.
The fixing member 41 is a cylindrical frame provided with side surfaces 411 to 414 orthogonal to the X axis and the Y axis, respectively, when viewed from the Z-axis direction. ˜Fourth swinging coils 441 to 444 are attached. Specifically, the first swing coil 441 is wound around the X axis and attached to the inner wall of the + X side surface 411 of the fixing member 41, and the second swing coil 442 is wound around the X axis. And attached to the inner wall of the side surface 412 on the -X side. The third swing coil 443 is wound around the Y axis and attached to the inner wall of the + Y side surface 413 of the fixing member 41, and the fourth swing coil 444 is wound around the Y axis. It is attached to the inner wall of the side 414 on the Y side.
The first to fourth swinging repulsion members 451 to 454 are plate-like members each made of a nonmagnetic conductive material, and the first to fourth swinging coils 441 to 444 are arranged on the outer peripheral surface of the lens driving device 42, respectively. It is attached so as to face. The first to fourth swinging repulsion members 451 to 454 may be square frame members.
As the swinging spring member 43, for example, as shown in FIG. 22B, an outer peripheral frame 43a, an inner peripheral frame 43b, and a movable frame 43c positioned between the outer peripheral frame 43a and the inner peripheral frame 43b. And a connecting piece 43p for connecting the outer peripheral frame 43a and the movable frame 43c at the central part on the + X side and the −X side, and a connection for connecting the movable frame 43c and the inner peripheral frame 43b at the central part on the + Y side and the −Y side. A leaf spring provided with the piece 43q is preferably used.

Next, the operation of the camera shake suppression device 40 will be described.
When an alternating current is supplied to the oscillating coil 441, a demagnetizing field due to the eddy current is generated in the first oscillating repulsive member 451 attached to the lens driving device 42 so as to face the first oscillating coil 441, and as a result. A repulsive force is generated between the first oscillating coil 441 and the first oscillating repulsive member 451, and this repulsive force causes the lens driving device 42 to rotate clockwise around the Y axis while moving in the −X direction. . Therefore, when a camera shake that rotates left about the Y axis while moving in the + X direction occurs in the lens driving device 42, the camera shake can be suppressed by flowing an alternating current through the first swinging coil 441. . In addition, when a camera shake that rotates clockwise around the Y axis while moving in the −X direction occurs in the lens driving device 42, the camera shake is suppressed by supplying an alternating current to the second swing coil 442. Can do.
When camera shake that rotates around the X axis while moving in the Y direction occurs, the camera shake can be suppressed by supplying an alternating current to the third swing coil 443 or the fourth swing coil 444. it can.

Embodiment 7 FIG.
FIGS. 23A and 23B are diagrams showing a configuration of a lens driving device 50 as an electromagnetic driving device according to Embodiment 7 of the present invention. FIG. 23A is a longitudinal sectional view, and FIG. It is a disassembled perspective view.
The lens driving device 50 includes a case 51, a lens holder 52 as a movable member, front and rear driving coils 53A and 53B, front and rear driving repulsion members 54A and 54B, and first to fourth supporting members. Coils 551 to 554 and first to fourth supporting repulsion members 561 to 564 are provided.
The lens holder 52 is, for example, a cylindrical member having a square shape in plan view, and the subject side when a lens (not shown) is mounted on the lens holder 52 is the front side in the Z-axis direction (+ Z side). Two directions orthogonal to each other are defined as an X axis and a Y axis, respectively.

The case 51 includes a square frame-shaped cover 51a disposed on the + Z side, a square frame-shaped base 51b disposed on the −Z side, and a frame portion 51c disposed between the cover 51a and the base 51b. A front driving coil 53A wound around the Z axis is attached to the periphery of the opening of the cover 51a on the lens holder 52 side (-Z side), and the lens holder of the opening of the base 51b A rear drive coil 53B wound around the Z-axis is attached to the peripheral portion on the 52 side (+ Z side). Specifically, the frame portion 51c includes side surfaces 511 to 514 that are orthogonal to the X axis and the Y axis, respectively, when viewed from the Z-axis direction, and the inner walls of the four side surfaces 511 to 514 are first to first, respectively. Four supporting coils 551 to 554 are attached. Specifically, the first support coil 551 is wound around the X axis and attached to the inner wall of the side surface 511 on the + X side of the frame 51c, and the second support coil 552 is wound around the X axis. And attached to the inner wall of the side surface 512 on the −X side. Further, the third support coil 553 is wound around the Y axis and attached to the inner wall of the side surface 513 on the + Y side of the frame 51c, and the fourth support coil 554 is wound around the Y axis − It is attached to the inner wall of the side 514 on the Y side.
The first to fourth support repulsion members 561 to 564 are plate-like members each made of a nonmagnetic conductive material, and the first to fourth support coils 551 to 554 are respectively formed on the outer peripheral surface of the lens holder 52. Mounted to face each other. The first to fourth support repelling members 561 to 564 may be square frame members.
The front and rear driving repulsion members 54A and 54B are annular members made of a non-magnetic conductive material. The front and rear driving coils 53A and 54A are provided at the + Z side end and the −Z side end of the lens holder 52, respectively. It is attached so as to face 53B.

Next, the operation of the lens driving device 50 will be described.
First, by applying an alternating current to the first to fourth support coils 551 to 554, a first magnetic material made of a nonmagnetic conductive material arranged to face the first to fourth support coils 551 to 554 is used. Eddy currents are generated in the first to fourth support repulsion members 561 to 564, and repulsive forces in the + X direction, −X direction, + Y direction, and −Y direction are applied to the lens holder 52. Thereby, the lens holder 52 can be held on the central axis without the spring member and the guide pin. That is, the lens holder 52 can be suspended in the air.
Next, when an alternating current is applied to each of the front and rear drive coils 53A and 53B, a repulsive force in the -Z direction acts on the front drive repulsion member 54A disposed on the -Z side of the front drive coil 53A. A repulsive force in the + Z direction acts on the rear driving repulsion member 54B disposed on the + Z side of the rear driving coil 53B. Therefore, if the current value applied to one of the front and rear drive coils 53A and 53B is made larger than the current value applied to the other, a thrust toward the drive coil having the smaller current value acts on the lens holder 52. Therefore, after the lens holder 52 moves to the driving coil side with the smaller current value, the repulsive force from the driving coil with the larger current value is balanced with the repulsive force from the driving coil with the smaller current value. Still at position. At this time, since the lens holder 52 is held on the central axis by the repulsive force from the first to fourth supporting coils 551 to 554, the lens holder 52 can be moved in the Z-axis direction without friction.

In the seventh embodiment, the lens holder 52 is suspended in the air on the central axis using the first to fourth support coils 551 to 554 and the first to fourth support repulsion members 561 to 564. However, in order to float the lens holder 52 in the air on the central axis, it is not always necessary to apply repulsive forces in the + X direction, the −X direction, the + Y direction, and the −Y direction, and at least 3 orthogonal to the Z axis direction. A repulsive force may be applied from the direction. Therefore, the outer diameter of the lens holder 52 may be a polygonal cylinder such as a triangular cylinder, a hexagonal cylinder, an octagonal cylinder, etc. in addition to a square cylinder, or a cylindrical shape.
In the above example, the lens holder 52 is suspended in the air on the central axis. However, by changing the magnitude of the alternating current applied to the first to fourth support coils 551 to 554, the lens holder 52 is moved. It can be moved in the X-axis direction or the Y-axis direction. Therefore, when the camera shake in the X-axis direction or the Y-axis direction occurs in the lens driving device 50, the magnitude of the alternating current supplied to the first to fourth support coils 551 to 554 is controlled, thereby Camera shake can be suppressed. That is, the lens driving device 50 of this example can be used as a lens driving device with a camera shake suppression function.
In the seventh embodiment, if the lens holder 52 is replaced with a lens driving device and the case 51 is a fixing member, camera shake is suppressed while the lens driving device is suspended in the air without using a spring member or a guide pin. Therefore, it is possible to configure a hand vibration suppression device that can perform the above-described operation.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the embodiment. It is apparent from the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

10 lens driving device, 11 case, 11a frame, 11b cover part,
11c base, 11k step, 12 lens holder, 12a body,
12b Stepped portion, 13A, 13B Spring member, 14 Driving coil,
15 Repulsion member for driving, 16 lens, 17 core member.

Claims (9)

An electromagnetic drive device comprising: a columnar or cylindrical movable member; a fixed member that supports the movable member in a swingable manner; and drive means that swings the movable member relative to the fixed member.
The driving means includes
A plate-like or annular driving repulsion member made of a nonmagnetic conductive material;
A driving coil disposed on one or both of one side and the other side in the thickness direction of the driving repulsion member so that the axial direction of the winding faces the thickness direction of the driving repulsion member And
One of the drive repulsion member and the drive coil is attached to the movable member, and the other is attached to the fixed member.   The electromagnetic drive device according to claim 1, wherein the movable member is supported by a spring member so as to be swingable with respect to the fixed member. The thickness direction of the drive repulsion member is the axial direction of the movable member, and the drive coil is disposed on one side and the other side of the drive repulsion member, respectively.
A guide hole provided in the movable member and extending in an axial direction of the movable member;
The electromagnetic drive device according to claim 1, further comprising a guide pin having both ends fixed to the fixing member and penetrating the guide hole. The thickness direction of the drive repulsion member is the axial direction of the movable member,
While arranging a plurality of sets of the drive repulsion member and the drive coil along the axial direction of the movable member,
In the thickness direction of the support repulsion member, a plate-like or annular support repulsion member made of a nonmagnetic conductive material disposed so that the thickness direction is perpendicular to the axial direction of the movable member, Comprising at least three sets of supporting coils arranged so that the axial direction of the winding faces the thickness direction of the supporting repulsive member;
2. The electromagnetic drive device according to claim 1, wherein one of the support repulsion member and the support coil is attached to the movable member, and the other is attached to the fixed member. The thickness direction of the drive repulsion member is the axial direction of the movable member, and the drive coil is disposed on one side and the other side of the drive repulsion member, respectively.
A plate-like or annular supporting repulsion member made of a nonmagnetic conductive material is further provided on the inner peripheral side of the drive coil so that the thickness direction is a direction perpendicular to the axial direction of the movable member. ,
2. The electromagnetic drive device according to claim 1, wherein one of the two types of repulsion members and the drive coil is attached to the movable member, and the other is attached to the fixed member.   The driving repulsion member is an annular member having a truncated cone side surface and arranged coaxially with the movable member, and the driving coil is arranged on one side and the other side in the thickness direction of the annular driving repulsion member. 2. The electromagnetic wave according to claim 1, wherein each of the driving repulsion members is arranged so that a ring portion thereof faces each of a winding portion of each of the two driving coils. Drive device. The movable member is supported by a spring member so as to be swingable with respect to the fixed member, and
The thickness direction of the driving repulsion member is a direction orthogonal to the axial direction of the movable member, and the axial direction of the winding is directed to the thickness direction of the driving repulsion member in the thickness direction of the driving repulsion member. The electromagnetic drive device according to claim 1, wherein the drive coil is arranged as described above.   A core member made of a soft magnetic material is disposed on any one or a plurality or all of the inner peripheral side, the outer peripheral side, and the back side which is the surface opposite to the driving repulsion member of the driving coil. The electromagnetic drive device according to claim 1, wherein: Either a protrusion that protrudes from the outer edge of the drive repulsion member to the outer periphery of the drive coil, or a protrusion that protrudes from the inner periphery of the drive repulsion member to the inner periphery of the drive coil The electromagnetic drive device according to any one of claims 1 to 8, wherein one or both of the drive repulsion members are provided.

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